1756-OF4 Output Wrong? Check Mode, RTB, and Scaling First
A field-first diagnostic sequence for 1756-OF4 analog output problems: channel mode, removable terminal block, scaling, and controlled electrical checks.
Manufacturer: Omron
Product No.: E5AC-RX2ASM-000
Country of origin:Japan
Product Type: Digital Temperature Controllers
Payment: T/T, Western Union
Weight: 3000g
Dimensions: 120 mm x 120 mm x 110 mm
Shipping port: Xiamen
Warranty: 12 months
Managing thermal profiles with high precision, the Omron E5AC-RX2ASM-000 serves as a high-density, 1/4 DIN process controller engineered for demanding industrial environments. This unit integrates a high-contrast, white PV display with a fast 50 ms sampling rate to deliver rapid, reliable closed-loop control. Designed for standard panel-mount configurations, it accommodates universal sensor inputs and features dual relay outputs to handle primary control loops and critical process alarms without requiring auxiliary transmitter modules.
| Specification Parameter | Technical Value |
|---|---|
| Manufacturer | Omron |
| Model / SKU | E5AC-RX2ASM-000 |
| Front Panel Size | 96 x 96 mm (1/4 DIN) |
| Supply Voltage | 100 to 240 VAC, 50/60 Hz |
| Power Consumption | 9.0 VA max. |
| Control Output 1 | Relay output (SPST-NO, 250 VAC, 3 A resistive load) |
| Control Output 2 | None |
| Auxiliary Outputs | 2 SPST-NO relays (250 VAC, 2 A resistive load) |
| Input Sensor Compatibility | Thermocouple (K, J, T, E, L, U, N, R, S, B, W, PL II), RTD (Pt100, JPt100), Analog (4-20 mA, 0-20 mA, 1-5 V, 0-5 V, 0-10 V) |
| Sampling Period | 50 ms |
| Control Method | ON/OFF control or 2-PID control (with auto-tuning) |
| Terminal Connection | Screw terminal block (M3) with integrated terminal cover |
| Operating Temperature | -10 to 55 degC (no icing or condensation) |
| Country of Origin | Japan |
| Shipping Weight (Calculated) | 0.45 kg |
| Package Dimensions (Calculated) | 120 mm x 120 mm x 110 mm |
| Terminal Number | Functional Circuit Assignment |
|---|---|
| 1 & 2 | Operating Power Supply Input (100 to 240 VAC, non-polarized) |
| 3 & 4 | Control Output 1 (Relay, SPST-NO) |
| 7 & 8 | Auxiliary Output 1 (Relay, SPST-NO) |
| 9 & 10 | Auxiliary Output 2 (Relay, SPST-NO) |
| 21, 22, 23 | Universal Sensor Input (RTD Phase A/B/B' or TC / Voltage / Current) |
The E5AC-RX2ASM-000 is a direct 1/4 DIN successor to legacy E5AN models. Unlike older iterations, this unit features a drastically reduced panel-mount depth of 60 mm, allowing installation in shallow enclosures. Note that while its parameter structure is highly aligned with legacy platforms, register map shifts may require verification if adapting existing Modbus communication loops via external gateways.
When utilizing the integrated 50 ms fast sampling mode, high-frequency electromagnetic fields from surrounding variable frequency drives (VFDs) can cause sensor value jitter or premature sensor-break errors (S.ERR). To prevent unstable process feedback, the input digital filter parameter (dFL) should be incrementally increased from the default 0.0 seconds to approximately 1.0 or 2.0 seconds in electrically noisy environments.
For initial thermal commissioning, configure the controller’s auto-tuning (AT) command only after the system has stabilized at room temperature. Executing auto-tuning from a hot state may cause the controller to calculate inaccurate PID gains, leading to cyclic overshoot. If wiring thermocouple inputs, always use the matching alloy-compensated extension wire directly to terminals 21 and 22 to prevent secondary cold-junction errors.
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| Country of origin |
Japan
|